diff options
| -rw-r--r-- | drivers/md/raid5.c | 165 | ||||
| -rw-r--r-- | include/linux/raid/raid5.h | 3 |
2 files changed, 163 insertions, 5 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 269b7771a30b..2ac2e56a1a40 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -134,6 +134,8 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) if (!test_bit(STRIPE_EXPANDING, &sh->state)) { list_add_tail(&sh->lru, &conf->inactive_list); wake_up(&conf->wait_for_stripe); + if (conf->retry_read_aligned) + md_wakeup_thread(conf->mddev->thread); } } } @@ -2645,18 +2647,80 @@ static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) } /* + * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) + * later sampled by raid5d. + */ +static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) +{ + unsigned long flags; + + spin_lock_irqsave(&conf->device_lock, flags); + + bi->bi_next = conf->retry_read_aligned_list; + conf->retry_read_aligned_list = bi; + + spin_unlock_irqrestore(&conf->device_lock, flags); + md_wakeup_thread(conf->mddev->thread); +} + + +static struct bio *remove_bio_from_retry(raid5_conf_t *conf) +{ + struct bio *bi; + + bi = conf->retry_read_aligned; + if (bi) { + conf->retry_read_aligned = NULL; + return bi; + } + bi = conf->retry_read_aligned_list; + if(bi) { + conf->retry_read_aligned = bi->bi_next; + bi->bi_next = NULL; + bi->bi_phys_segments = 1; /* biased count of active stripes */ + bi->bi_hw_segments = 0; /* count of processed stripes */ + } + + return bi; +} + + +/* * The "raid5_align_endio" should check if the read succeeded and if it * did, call bio_endio on the original bio (having bio_put the new bio * first). * If the read failed.. */ -int raid5_align_endio(struct bio *bi, unsigned int bytes , int error) +static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error) { struct bio* raid_bi = bi->bi_private; + mddev_t *mddev; + raid5_conf_t *conf; + int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); + mdk_rdev_t *rdev; + if (bi->bi_size) return 1; bio_put(bi); - bio_endio(raid_bi, bytes, error); + + mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata; + conf = mddev_to_conf(mddev); + rdev = (void*)raid_bi->bi_next; + raid_bi->bi_next = NULL; + + rdev_dec_pending(rdev, conf->mddev); + + if (!error && uptodate) { + bio_endio(raid_bi, bytes, 0); + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_stripe); + return 0; + } + + + PRINTK("raid5_align_endio : io error...handing IO for a retry\n"); + + add_bio_to_retry(raid_bi, conf); return 0; } @@ -2665,7 +2729,7 @@ static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio) mddev_t *mddev = q->queuedata; raid5_conf_t *conf = mddev_to_conf(mddev); const unsigned int raid_disks = conf->raid_disks; - const unsigned int data_disks = raid_disks - 1; + const unsigned int data_disks = raid_disks - conf->max_degraded; unsigned int dd_idx, pd_idx; struct bio* align_bi; mdk_rdev_t *rdev; @@ -2699,13 +2763,25 @@ static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio) rcu_read_lock(); rdev = rcu_dereference(conf->disks[dd_idx].rdev); if (rdev && test_bit(In_sync, &rdev->flags)) { - align_bi->bi_bdev = rdev->bdev; atomic_inc(&rdev->nr_pending); rcu_read_unlock(); + raid_bio->bi_next = (void*)rdev; + align_bi->bi_bdev = rdev->bdev; + align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); + align_bi->bi_sector += rdev->data_offset; + + spin_lock_irq(&conf->device_lock); + wait_event_lock_irq(conf->wait_for_stripe, + conf->quiesce == 0, + conf->device_lock, /* nothing */); + atomic_inc(&conf->active_aligned_reads); + spin_unlock_irq(&conf->device_lock); + generic_make_request(align_bi); return 1; } else { rcu_read_unlock(); + bio_put(align_bi); return 0; } } @@ -3050,6 +3126,72 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski return STRIPE_SECTORS; } +static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) +{ + /* We may not be able to submit a whole bio at once as there + * may not be enough stripe_heads available. + * We cannot pre-allocate enough stripe_heads as we may need + * more than exist in the cache (if we allow ever large chunks). + * So we do one stripe head at a time and record in + * ->bi_hw_segments how many have been done. + * + * We *know* that this entire raid_bio is in one chunk, so + * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. + */ + struct stripe_head *sh; + int dd_idx, pd_idx; + sector_t sector, logical_sector, last_sector; + int scnt = 0; + int remaining; + int handled = 0; + + logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); + sector = raid5_compute_sector( logical_sector, + conf->raid_disks, + conf->raid_disks - conf->max_degraded, + &dd_idx, + &pd_idx, + conf); + last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); + + for (; logical_sector < last_sector; + logical_sector += STRIPE_SECTORS, scnt++) { + + if (scnt < raid_bio->bi_hw_segments) + /* already done this stripe */ + continue; + + sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1); + + if (!sh) { + /* failed to get a stripe - must wait */ + raid_bio->bi_hw_segments = scnt; + conf->retry_read_aligned = raid_bio; + return handled; + } + + set_bit(R5_ReadError, &sh->dev[dd_idx].flags); + add_stripe_bio(sh, raid_bio, dd_idx, 0); + handle_stripe(sh, NULL); + release_stripe(sh); + handled++; + } + spin_lock_irq(&conf->device_lock); + remaining = --raid_bio->bi_phys_segments; + spin_unlock_irq(&conf->device_lock); + if (remaining == 0) { + int bytes = raid_bio->bi_size; + + raid_bio->bi_size = 0; + raid_bio->bi_end_io(raid_bio, bytes, 0); + } + if (atomic_dec_and_test(&conf->active_aligned_reads)) + wake_up(&conf->wait_for_stripe); + return handled; +} + + + /* * This is our raid5 kernel thread. * @@ -3071,6 +3213,7 @@ static void raid5d (mddev_t *mddev) spin_lock_irq(&conf->device_lock); while (1) { struct list_head *first; + struct bio *bio; if (conf->seq_flush != conf->seq_write) { int seq = conf->seq_flush; @@ -3087,6 +3230,16 @@ static void raid5d (mddev_t *mddev) !list_empty(&conf->delayed_list)) raid5_activate_delayed(conf); + while ((bio = remove_bio_from_retry(conf))) { + int ok; + spin_unlock_irq(&conf->device_lock); + ok = retry_aligned_read(conf, bio); + spin_lock_irq(&conf->device_lock); + if (!ok) + break; + handled++; + } + if (list_empty(&conf->handle_list)) break; @@ -3274,6 +3427,7 @@ static int run(mddev_t *mddev) INIT_LIST_HEAD(&conf->inactive_list); atomic_set(&conf->active_stripes, 0); atomic_set(&conf->preread_active_stripes, 0); + atomic_set(&conf->active_aligned_reads, 0); PRINTK("raid5: run(%s) called.\n", mdname(mddev)); @@ -3796,7 +3950,8 @@ static void raid5_quiesce(mddev_t *mddev, int state) spin_lock_irq(&conf->device_lock); conf->quiesce = 1; wait_event_lock_irq(conf->wait_for_stripe, - atomic_read(&conf->active_stripes) == 0, + atomic_read(&conf->active_stripes) == 0 && + atomic_read(&conf->active_aligned_reads) == 0, conf->device_lock, /* nothing */); spin_unlock_irq(&conf->device_lock); break; diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h index 03636d7918fe..d8286db60b96 100644 --- a/include/linux/raid/raid5.h +++ b/include/linux/raid/raid5.h @@ -227,7 +227,10 @@ struct raid5_private_data { struct list_head handle_list; /* stripes needing handling */ struct list_head delayed_list; /* stripes that have plugged requests */ struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */ + struct bio *retry_read_aligned; /* currently retrying aligned bios */ + struct bio *retry_read_aligned_list; /* aligned bios retry list */ atomic_t preread_active_stripes; /* stripes with scheduled io */ + atomic_t active_aligned_reads; atomic_t reshape_stripes; /* stripes with pending writes for reshape */ /* unfortunately we need two cache names as we temporarily have |